In a process of manufacturing a semiconductor device, a film may be formed by performing atomic layer deposition (ALD) on a semiconductor wafer (hereinafter, referred to as “wafer”). As an apparatus for performing such ALD, for example, there has been known an apparatus in which a rotary table with a plurality of wafers placed thereon is rotated to revolve the wafers so that the wafers repeatedly pass through a process-gas supplying region arranged in a diametric direction of the rotary table.
In an apparatus for performing dry etching on a wafer, however, there may be a case where an etching rate is adjusted so that a concentric distribution around a central portion of the wafer is achieved. In that case, it is necessary to obtain a concentric film thickness distribution around the central portion of the wafer in a film-forming process for the wafer which is a pre-process of the dry etching. In the aforementioned apparatus in which the wafers are revolved, however, a film formed on the wafer tends to have a film thickness distribution around a central portion of the rotary table, resulting in a problem that it is difficult to obtain the concentric film thickness distribution around the central portion of the wafer.
Since the film thickness distribution formed on the wafer depends on a wafer temperature, a concentric film thickness distribution can be obtained by adjusting a temperature distribution of the wafer. In some related art, heating lamps are utilized in film-forming apparatuses in which wafers are revolved. Specifically, there are known a technique of modifying a thin film by heating a wafer to a temperature higher than a film forming temperature, a technique of densifying a reaction product by means of heating, and a technique of performing auxiliary heating to a temperature higher than a pyrolysis temperature of ozone gas. Further, it is also known to control a plurality of heating lamps such that an in-plane temperature difference does not occur. However, the aforementioned techniques are different from a configuration of the present disclosure.